Ok, with Kowlaski's setup, I can't seem to actually get a binary. I can use the simulator, but can't actually create a file to put on an EEPROM.

I tried "save code", but its always just zeroes. Feel like I'm missing a step.

This thing is an actual assembler, and not just a sim, right?

I'm ...

Why is the (;clear Irq) comment located on a blank line?
Maybe something like sta zploc should be there?

Very nice project Brad, looks great!

It would be cool if you can use the 65C02 to control the other AVR USART for serial communication.

Happy Holidays to you and everyone!
Ron

Also, the Sandisk PDF document shows that Vcc is Pin 13 and Pin 38.

"-VS1 -VS2 - pin 33, 40
Voltage Sense Signals. -VS1 is grounded so that the CompactFlash Card CIS can be
read at 3.3 volts and -VS2 is open and reserved by PCMCIA for a secondary voltage."

Maybe check these pins?

Just a quick thought, how about a flip-flop latching the RDY line at CS, the AVR can take as long as it likes to clear the FF and release RDY.

Just another possible idea for using an AVR without using RDY or a VIA interface.

The main problem it seems is the delay of the AVR Data Direction Register since it has to be controlled in software.
If 2 AVR ports were used, 1 port set for input and 1 port set for output then the S/W delay of port ...

Wouldn't it be easier to use the AVR or PIC programmed as a typical UART and have the 6502 access the AVR/PIC?
The AVR/PIC would process the incoming serial data and when data is available have a pin go low then the 6502 can read the 8 bit AVR/PIC data pins.
For transmit just put 8-bits of data from ...

Figure 7 on page 24 of the 26C92's data sheet shows the hookup for using a crystal as the frequency source.

26c92_oscillator.gif

C1 and C2 are dependent on the crystal used. I can't vouch for the performance of this circuit, as I haven't tried it.

I used a crystal with the 26C92 when I first ...

Nice work!

Use Atmel software ISP (free), tested with version 6.7
You can write the code with Atmel's WinCUPL software. There's a bit of hoop-jumping involved in getting WinCUPL. Contact me via PM if you need help.

That's true. I should have mentioned that.

I do use WinCUPL 5.30.4 for writing the code ...

Could someone point me to a resource on how to make a JTAG programming circuit, and what other external tools I will need?

I built this one for Atmel CPLD's and it works fine.
http://www.pyroelectro.com/tutorials/byteblastermv/schematic.html

I have tested it with the Atmel ATF1504AS and ...

More likely, though, your clock speed limit is due to insufficient drive on some signals.

I also have 128k of Dallas 100ns NVRAM on board and I'm decoding the 816 bank address using the WDC schematic which uses a AC573 and a AC245 on the data bus. All things considered 10Mhz is pretty good in ...

So it must be that SCSI operation is right on the ragged edge at 14.161 MHz.
I ended up reinstalling the 25 MHz oscillator that was in POC, slowing the clock to a sedate 12.5 MHz.

I have a wire-wrapped sbc board with an 816 that runs fine and (temp stable) at 10 Mhz (20 Mhz half can osc). I have ...

I agree also. Zero page is a very special place.